The variety of colors of emergency vehicle lights — and what they signify —can be confusing, especially for motorhomers who travel from state to state.

Police cars, fire trucks and ambulances use flashing, rotating or oscillating lights to notify their approach to other motorists. Tow trucks, utility trucks, funeral lead cars, and other vehicles also use distinguishing lights.

Max Durbin, chair of FMCA’s Governmental and Legislative Advisory Committee, said the lack of uniformity of lens colors used by these vehicles can be unsafe. “Motorhomers and other motorists are unable to immediately detect what type of vehicle is approaching and whether or not they have a legal right-of-way.”

Frank Brodersen, a member of the Governmental and Legislative Affairs Committee, looked into the emergency lighting issue.

He contacted the National Highway Traffic Safety Administration and various police departments, departments of motor vehicles and departments of transportation. He also exchanged information with manufacturers and distributors of emergency lighting.

From those sources, he developed the following information.

Lack of uniformity

There is no national standard for visual warning devices, Brodersen found. Each state may establish its own laws or administrative rules.

Flashing or oscillating red/blue lights always identify emergency vehicles, even when used in conjunction with other colors. For instance, emergency vehicles may display red/blue lights frequently used in combination with amber or white lights.

When to yield

While lighting combinations vary across jurisdictions, red/blue always indicates an emergency vehicle. And one thing is certain: You must yield the right-of-way to emergency vehicles.

The National Committee of Uniform Traffic Laws and Ordinances, an independent, privately funded group, has written emergency vehicle ordinances that are used in approximately 40 states. Here is NCUTLO’s recommendation concerning yielding to an emergency vehicle:

When an emergency vehicle approaches, the driver of every other vehicle shall yield the right-of-way and immediately drive to a position parallel to, and as close to, the right-hand edge or curb of the roadway clear of any intersection. Stop if it is safe to do so, and remain in such position until the emergency vehicle has passed.

Amber lights

Amber warning lights, visible from either the front or rear of vehicles, are often used by construction or work vehicles. Utility trucks (electric, gas, water), cable/phone companies and state highway maintenance vehicles also display amber lights.

As a rule of thumb, it’s not necessary to yield to vehicles displaying only amber lights. However, amber lights in conjunction with red (as on the rear of school buses), indicates that you must stop and not pass until the red lights are turned off.

In any case, amber lighting should alert you to hazards, stopped traffic or a slow-moving vehicle. Exercise caution, drive courteously and be alert for unsafe conditions.

Working zones

Amber lights used in conjunction with bright orange warning signs indicate a "hazardous" situation. An example is a highway construction or work zone. Ignoring the posted speed limit where amber lights are used with orange signage can be both deadly and costly.

Enforcing the speed limits in hazardous work zones is a goal of all states. Many motorhome travelers are familiar with the national "give them a brake" campaign. Motorists who do not reduce their speed in work zones could face substantial fines and/or time in jail.

Summary

Emergency vehicle signals and laws vary across jurisdictions, so always check with the state police, highway patrol or department of public safety for laws specific to your area of travel. Here’s a general summary:

Amber with red — Vehicles that frequently stop, such as school buses. Do not pass them when red lights are flashing.

Move over

It's important to know that many U.S. states have enacted "move-over" laws, which require motorists to move over and slow down for authorized emergency vehicles stopped on the side of the highway.

The laws are designed to protect police officers, paramedics, firefighters and other emergency personnel from passing motorists.

Move-over laws very by state, but general stipulations include:

When traveling on multilane highways and in the direction of an emergency vehicle that has its emergency lights activated, drivers must vacate the lane closest to the emergency vehicle, as soon as it is safe to do so.

On two-lane highways, drivers must slow to a speed below the posted limit and be prepared to stop.